FI95000B - Shoe spring and stabilizer - Google Patents

Description

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This invention relates generally to footwear, and more particularly to a sports shoe comprising an midsole having a heel and an outsole.

In walking or running, the whole foot is most often used at the beginning of the movement with a heel stroke, after which the movement moves to the middle of the foot and continues with a pushing movement from the front of the foot and the toes. Prior to the kan-10 kick-off, the foot is in the outward position, i.e. it is directed upwards from the ground at a certain angle and has turned outwards. During a heel stroke, the ankle, knee, and hip bend to lighten and dampen the impact, after which the foot moves and pivots inward as a motion called the in-15 turn of the foot.

During this period of operation, it is desirable to be able to dampen the impact energy of the foot as much as possible, in relation to the stability of the foot's contact with the ground, so that the runner does not suffer a chronic or traumatic injury. If possible, and still with good running stability, due to the energy efficiency, it is also desirable that such damped impact energy be able to be recovered and returned to the foot during the forward-pushing phase of the running motion. It is also desirable to be able to limit excessive foot rotation or rotation when the foot touches the ground, which in turn is related to both medical and running severity factors.

In the shoe industry, spring devices are known to be placed on the soles of shoes and specifically on their heels to recover the impact energy generated by the impact of the foot when running and to return at least part of this energy to the foot as the foot rises. It is also known that longitudinal stiffeners are applied to the sole of a shoe to eliminate the effect of excessive exit or retraction of the foot 35 when running.

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For example, U.S. Patent Nos. 4,486,964 and 4,506,460 (M.F. Rudy) disclose various "spring moderators" made of plastic and hardened steel, the primary function of which is to distribute the impact forces of the foot more evenly and quickly to the inflatable parts of the sole below them. The horseshoe-shaped heel of their moderators is reported to act in a manner similar to the Belleville spring with the foot to recover and restore energy when running, and according to one structure, it is also reported to stabilize the ankle vertically.

U.S. Patents 2,357,281 and 2,394,281 (V.P. Williams) disclose a shock absorbing heel unit for shoes with a steel spring.

15 U.S. Patent 4,709,489 / K.F. Welter discloses a spring device for a shoe heel comprising a steel plate supported at its side edges by a U-shaped non-compressible support member. In addition to the base spring function, the support part is also reported to stabilize the shoe base • i 20 laterally.

U.S. Patent 4,881,329 / K.J. Crowley discloses another energy recovery carrier spring which can be made by compression from high tensile materials such as graphite and / or glass fibers and. 25 of plastic.

Etonic Company, Brockton / Massachusetts, has promoted a stability system that includes various forms of “DRP Plus Plate” structures made of a combination of graphite, acrylic, and fiberglass and placed at various points on the soles of shoes • made by this company to compensate shoe users. problems with excessive foot rotation and / or external circulation.

The sports shoe according to the invention is characterized in that it comprises a resilient plate fitted to the heel of the midsole material in a horizontal position above the outsole so that the plate is covered with the midsole material, the plate being molded into the midsole to prevent relative movement in the midsole. ; the plate-5 has a pair of side edges, a front and a rear end, and at least one opening defining a rearwardly extending spring member; the spring member is inclined upwardly and extends rearwardly relative to the plate, having a rear portion adapted to be positioned below the heel of the wearer; and that the intermediate base 10 has a recess arranged below the spring member and above the outer base.

The sports shoe according to the invention thus has a device which is placed in the midsole of the sports shoe and which combines the advantages of a base spring for damping, recovering and recovering running energy from the foot and a stabilizing plate which enhances the excessive ejection and retraction of the foot. . The device is one of its manufacturing methods. and due to the material, simple, inexpensive and also 20 very light.

The device has a thin heel-sized plate made of a durable, rigid, yet flexibly flexible composite structure of thermoplastic and carbon fiberglass fabric and placed in the heel of the midsole of a sports-25 shoe. The plate has two upwardly turned side edges, a front end and a rear end, and a rearwardly facing, upwardly sloping and vertically acting spring part integral with the structure. The spring is delimited in the plate by two openings extending from the rear-30 end of the plate to its front end. The spring part is intended under the heel bone of the foot and the midsole of the shoe is cut back from the area under the spring part so that the spring part can bend freely downwards under the effect of the heel forces. A stop may be molded into the outsole of the shoe to limit the maximum downward deflection of the spring-35 portion.

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In order to facilitate an understanding of the device according to the invention and the many advantages associated therewith, its preferred structures will now be described in detail with reference to the accompanying drawings, which will be briefly described below.

Fig. 1 is a side view of a right foot sports shoe heel showing the device according to the invention in a broken line, Fig. 2 is a bottom plan view of the shoe heel shown in Fig. 1 taken along line 2-2 of Fig. 1, the device according to the invention now in broken lines, Fig. 3 is a partial side section of the shoe sole and the device of the present invention shown in Figs. 1 and 2 taken along line 3-3 of Fig. 2; Fig. 4 is a partial cross-sectional rear view of the shoe base and the device of Figs. 1-3 taken along line 4-4; 4, and ... Fig. 5 is a perspective view of a base spring and stabilizing plate device according to the present invention 20.

As can best be seen from Figures 1 and 2, the ur pendulum shoe 1 comprises an upper 2 and a sole part 3. The shoe 1 can be called a game, running or training shoe depending on the application or shape.

. 25 The shoe upper 2 can be of high or low design and can be made of leather and / or many different artificial materials, including vinyl. The sole part 3 generally comprises a midsole 4 and an outer sole 5. The sole part 3 may also have an insole-forming layer (not shown) which is either integral with the midsole structure or is a separate part shaped to fit snugly against the sole of the shoe wearer and distribute to the midsole of the foot load.

Typical midsole materials for modern ur-35 swing shoes include foamed ethylene vinyl acetate 5 95000 (EVA) and foamed polyurethane (PU), which can be molded to give midsoles many desired functional and decorative details and dimensions, and which can be incorporated into the molding process. a device according to the present invention.

Typical materials used to make the outsole 5 are again various synthetic rubbers and non-foamed polyurethane. Similarly to the materials used for the midsole 4, suitable structural features or patterns may be incorporated into the bottom surface or outer edges of the outsole 5 when casting them, for example the plateaus 6 shown in the figure. An example of an outsole pattern is shown in the co-pending U.S. Pat. , filed 04.05.90.

Figures 3-5 show by way of example a preferred structure of a carrier spring and stabilizer device 10 for sports shoes according to the present invention. Device 10 is shown. only for the shoe 1 of the right foot, but it naturally comprises two such devices, i.e. one device for each shoe, the device for the left shoe being symmetrical with the device 10 shown in the figure.

The device 10 comprises a thin, flat plate 12 corresponding to the size of the shoe sole 25, which is made of a durable, rigid, yet resiliently flexible material, as described below. The device is immersed in an approximately horizontal position in the flexible material forming the base of the midsole 4 as it is cast, as already mentioned.

- The plate 12 is preferably made by stamping from a large flat plate of material and then shaped as described below. The plate 12 has two upwardly turned side edges 14A and 14B, 35 front end and rear end 16 and 18, respectively, and a rearwardly facing, upwardly inclined and vertically acting spring portion 20 integrally associated with its structure formed by two openings 22A and 22B in the plate 12. extending from the rear end 18 of the plate 12 to its front end.

The disclosed device 10 can be made of a variety of materials, including hardened spring steel, but the preferred material for this exemplary device 10 is a laminate combination with a thermoplastic with surface sheets of woven fibers 10 or a sheet of carbon and glass fibers. U.S. Patent 4,778,717 further discloses a material marketed by Medical Materials Corporation for biopharmaceutical applications as the TL-61e trademark and for commercial purposes as the Novetek trademark.

15 The recommended material is available in sheets with a turnover of 0.035 to 0.055. The material has a tensile strength of about 1650 to 2900 N / cm 2 (24,000 to 42,000 pounds per square inch (psi)), depending on its strength, and a modulus of elasticity of 910,000 to 2,500,000 N / cm 2 (1,300,000 to 3,600,000 psi). It is easy to cut, saw or punch with a relatively inexpensive tool as shown in the preferred construction.

In addition, the material can be formed using heat to give various shapes, for example the upward inclination of the spring part 20 and the upwardly turned side edges 14Ά, 14B, by heating the material at relatively low temperatures (176 ° C to 260 ° C) in suitable equipment. As the temperature of the shaped material decreases to match the room temperature, the flexibility 30 and durability of the material are completely restored. Material life tests have been performed by the assignee of this patent application using test specimens for the shape of the device 10, which corresponded approximately to the exemplary structure shown in the figures, with the spring member 20 bent into a flush position with the plate 12 six times per second. The test pieces withstood more than a million bends without breaking and did not show any cracks, fatigue cracks or loss of strength or flexibility of the measurable material.

Thus, it can be concluded that the physical properties of the preferred composite material correspond to the properties of well-hardened steel alloys, although the weight and manufacturing costs of the tested material are significantly lower compared to the corresponding steel parts.

The device 10 is embedded in the heel area of the material forming the midsole 4 of the shoe so that the rear part of the spring part 20 is below the heel of the shoe wearer's foot and the layer 24 of midsole material 4 covers the part 20. The midsole 4 is cut back from 26 below the spring part. bend freely downwards.

The layer 24 acts as a resilient part between the muscle tissue under the heel of the foot and the upper surface of the spring part 20 and also distributes the load Φ: applied to the spring part of the foot more evenly. Layer 24 somewhat reduces the overall flexibility of the spring member 20 as seen from the shoe base and also the ability of the spring member to restore bending energy as the heel rises, mainly due to energy loss due to heat dissipation in layer 24 during compression and expansion. However, this small loss of elasticity 25 is acceptable because the comfort of the foot in the shoe has been improved and it is possible to prevent an overly flexible heel spring function. With the exception of this effect and the deflection-limiting condition described below, the movement of the spring member is fairly linear over the entire deflection range intended for it and, in addition, very efficient (> 85%),. when it comes to returning the bending energy stored in the spring portion during the heel stroke back to the shoe wearer's foot as the heel rises.

In the preferred construction, the side edges 35 14A, 14B of the plate 12 are shown turned upwards, but they can also be turned downwards as a suitable construction. The inverted edges stiffen the device considerably longitudinally and, being somewhat outside the heel of the shoe wearer on either side of the heel, act in a manner similar to the outer supports of a canoe structure and prevent excessive foot ejection and retraction during normal walking or running. The inverted edges also promote the attachment of the device 10 to the material of the midsole 4 and prevent the device from moving if it detaches from the midsole material for any reason.

For example, in the preferred construction shown, a stop 28 is alternatively molded into the outsole 5 of the shoe just below the spring member 20 and the heel to define the maximum downward deflection of the spring member 15 during large heel strokes that occur when jumping. The vertical operation of the stop 28 is such that the stop does not contact the spring member 20 when standing or walking normally, but only begins to operate when the spring member bends so much that its desired maximum downward deflection is exceeded, which occurs when jumping or running hard.

It will be appreciated by those skilled in the art from the foregoing description that many changes may be made to the structure, materials and fabrication methods of the base spring and stabilizer plate, depending on the particular case or application involved. Accordingly, the structures shown in the figure and described above are intended only by way of example and the scope of the present invention is limited only by the following claims.

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Claims (6)

A sports shoe comprising an upper leather (2), a bottom (3) attached to the upper leather comprising a middle bottom 5 (4) having a heel portion, and an outer bottom (5), characterized in that it comprises a flexible disc (12). which is arranged in the heel portion of the material of the intermediate bottom (4) in a horizontal position above the outer bottom (5) so that the disc 10 is covered by the intermediate bottom material (24), the disc (12) being molded in the intermediate bottom (4). to prevent relative movement in the middle bottom, the disc (12) has a side edge pair (14A, 14B), a front and rear end (16, 18) and at least one opening 15 defining a rearwardly directed spring member (20), the spring member (20) is upwardly inclined and rearwardly directed in relation to the disk (12), showing a rear portion arranged to be positioned below one. the heel of the user, and that the intermediate bottom (4) has a recess arranged below the spring member (20) and the upper outer bottom (5). Sport shoe according to claim 1, characterized in that the spring means (20) are defined by two open openings (22A, 22B) extending from the rear end (18) of the disc (12). Sports shoe according to claim 1, characterized in that the disc (12) is formed of composite material comprising thermoplastic resin and carbon-glass fiber tissue. 4. A sports shoe according to claim 1, characterized in that the side edges (14A, 14B) of the disc (12) are folded up. Sports shoe according to claim 1, characterized in that the side edges (14A, 14B) of the disc (12) are folded down-tight. 35 12 95000 Sport shoe according to claim 1, characterized in that a stopper (28) of flexible material is provided at the outer bottom (5), below the spring means (20). • «